1. Field of the Invention
This invention relates to apparatus for making continuous chain, of synthetic plastic or other desired materials.
2. Description of the Prior Art
Various machines have heretofore been proposed for the making of chain composed of a continuous series of links in engagement.
Klatte, in U.S. Pat. No. 537,780, discloses a roll for rolling chain out of malleable metal but does not show the simultaneous formation of a plurality of links, then advancing the chain thus formed and successively forming pluralities of links in series and continuous with the links previously formed.
Herron, in U.S. Pat. No. 923,521, forms a solid link which is manually placed in the end cavity of a mold, then closing the mold and forming a link interlooped with the end link of the chain previously formed, and the operation is repeated link by link.
Leblanc, in U.S. Pat. No. 1,083,841, shows a four part mold in which the parts are hinged together and provided with quarter grooves which coact to form a semicircular channel open at the end of the mold and adapted to receive by manual insertion the last link of a previously cast section so that this section may be connected with the next section cast.
Craven, in U.S. Pat. No. 1,242,325, shows apparatus for forging links of chain which is unsuited for making chain of plastic or by injection molding.
Cowles, in U.S. Pat. No. 1,431,443, shows apparatus for rolling chain without welding but this bears little resemblance to the apparatus of the present invention.
Fawcett, in U.S. Pat. No. 1,656,371, shows apparatus employing a mult-part mold for cast steel chain but in which the links must be placed in the mold by hand to achieve a continuous length of chain.
Kloss, in U.S. Pat. No. 2,348,979, shows a mold for casting metal chain in said molds and in which the operator has to arrange the components. An inherent limitation on the length of the chain is imposed by the length of the mold.
Morin, in U.S. Pat. No. 2,388,986, shows apparatus for producing intercoupled relatively movable castings in which the links must be trimmed and cut apart and the ends of the links formed in another operation to make a uniform chain.
Deiss, in U.S. Pat. No. 2,498,031, shows a chain making machine employing a two-part mold for making one link at a time with grippers for trimming off the gates and locating the molded links which has little resemblance to the apparatus of the present invention either as to the molds or their utilization.
Ronceray, in U.S. Pat. No. 2,606,348, shows a mold for the fabrication of metallic chains by the lost wax or investment casting process and with which only a limited length of chain can be made. The molds must be carefully taken apart to remove the chain and reassembled by hand for the next casting operation.
Heichel et al., in U.S. Pat. No. 3,328,848, shows a chain molding device with four separable mold sections required to form a single link and a holding device which must be rotated 90.degree. and back after each molding cycle to make a chain.
Ross, in U.S. Pat. No. 3,469,284, shows chain making apparatus with separable dies having cavities for forming a plurality of connected links. Manual insertion of an end link of a previously molded chain is required to attain continuity.
Funke, in U.S. Pat. No. 3,490,100, shows a mold for molding link chains of plastic material which also requires manual insertion of an end link of a previously molded chain to attain continuity.
Nelson, in U.S. Pat. No. 3,507,112, shows apparatus for casting chains with elliptical links, a four part mold being employed, one part of which is mounted in a stationary position, the other part being separable by horizontal movement and with passageways to form a plurality of links. No provisions are made for advancing the molds from their paths of movement or for continuity.
Russo, in U.S. Pat. No. 3,588,959, shows apparatus for molding plastic link chain employing four dies separable outwardly for release of the chain after molding. The feed neck portions require a physical pull to free the links. The length of the chain is limited by the length of the mold although the next section may be formed and integrally engaged by manually placing the last or free link into the last molding cavity and then molding the length permitted by the length of the mold.
Florjancic, in U.S. Pat. No. 3,718,420, shows apparatus for producing with multipart molds one annularly closed interconnected element by injection, the parts of the molds being in two planes of division perpendicular to one another with recesses in one plane being designed to receive prefabricated interconnected elements for connection by the new interconnected elements formed by molding.
None of the prior art devices show apparatus in which molded sections of chain are molded in and advanced by sets of molds while being retained by certain of the dies and with return of a set of dies to a beginning location for advance with the chain upon molding.
None of the prior art devices show apparatus or methods utilizing continuously advanced side dies for molding a link into a previously molded length of chain to provide a continuous chain.